Designed by: Yoshitsuna Kobayashi (creator of Marl Kingdom), possibly others
Influenced by: Tactics Ogre, Final Fantasy Tactics
Series: Not a coherent series, although the individual games borrow from each other, sometimes nonsensically.
Legacy: Not much yet...
Relative newcomers to the scene, Nippon Ichi's RPGs have made a name for themselves for their generally light-hearted storylines and insanely deep puzzle-battle play. And also, by taking powergaming to perhaps the most absurd extent imaginable. But I get ahead of myself.
Nippon Ichi occasionally makes other games, but their tactical RPGs are probably what they're most known for. They don't actually differ all that much from each other in the basics, a Final Fantasy Tactics-style tactical battle where the player's characters attempts to defeat enemy characters, both roaming around (usually) an isometric grid with a height component.
The specifics may change considerably between games, but one aspect that seems more or less consistent is a general abstractness of the fighting. T
he most famous installment, Disgaea, for instance, has its geopanels, which are basically puzzle pieces sitting on the ground, waiting for one side or the other to take advantage of them. Why? Because it makes the fighting more interesting, that's why. Don't be a troublemaker.
On to the powergaming. A trademark aspect of Nippon Ichi games is an unusually high level cap. Sometimes this is revealed to a newbie player early on, by showing him an enemy with a vastly higher level than would ordinarily be possible. Even winning the game doesn't typically require a level higher than 100.
Near the end of the game bonus dungeons become available with hugely powerful opponents, giving players something to use ultra-high level characters for. Usually it requires some special trick, like attacking own characters for the experience 6r abusing geopanels, or similar tactics. The maximum level in a Nippon Ichi tactical game is usually 9,999, a value that would probably have made Gary Gygax sick.
And yet... is this not the spirit of the old games? The thrill of powergaming taken to its utmost level? The brutal slaying of Odin, who "only" has 300 hit points? Killing allies for the experience gain?
Could it be that we have seen the ghosts of all those countless ancient old-school RPG characters, and that they've all become explosive zombie penguins with bat wings?